The upper limb Flashcards
Pectoral girdle
Comprises the clavicle and shoulder. Links free limb to axial skeleton at sternoclavicular joint
Movements of Pectoral girdle
Scapula retraction & protraction
Scapula elevation & depression
Superior rotation (abduction) & inferior rotation (adduction)
Scapula
Triangular, flat bone covering the posterior and lateral surface of ribs 2-7
How many angles, borders, protuberances and surfaces does the scapula have?
3 of each (12 in total)
Sternoclavicular joint
Saddle shaped synovial joint. Has two cavities divided by a fibrocartilaginous disc (intra-articular disc)
Four ligaments
A & P sternoclavicular lig
Costoclavicular lig
Interclavicular lig
Acromioclavicular joint
Has a wedge shaped fibrocartilaginous intra-articular disc.
Anterior muscles of Pectoral Girdle
Axial to Pec G
Subclavius
Pectoralis minor
Serratus anterior
Axial to humerus
Pectoralis major
Posterior muscles of Pec G
Axial to Pec G
Trapezius
Levator scapulae
Rhomboid minor
Rhomboid major
Axial to humerus
Latissimus dorsi
Pec G to humerus
Supraspinatus
Infraspinatus
Teres Minor
Subscapularis
Deltoid
Teres Major
Coracobrachialis
Biceps brachii
Triceps brachii
Origin
Moves the least
Insertion
Moves the most
Pectoralis major
Adducts the humerus
Internally rotates humerus
Can help protract scapula by pulling on humerus
Subclavius
C5
Braces clavicle
Weak depressor of scapula
Pectoralis minor
Depresses scapula
Helps protract scapula
Serratus anterior
Protracts scapula
Lower fibres help superiorly rotate scapula
Trapezius
Superior - elevates scapula
Middle - retracts scapula
Lower - depresses scapula
Sup & inf - superior rotation of scapula
Levator scapula
Elevates scapula
Helps inferiorly rotate scapula
Rhomboid minor & major
Retracts scapula
Elevates scapula
Helps inferiorly rotate scapula
Latissimus dorsi
Adducts the humerus
Internally rotates humerus
Lower fibres can depress scapula by pulling on humerus
Can help inferiorly rotate scapula by pulling on humerus
Elevators of scapula
Trapezius
Levator scapulae
Rhom major and minor
Depressors of scapula
Subclavius
Pectoralis minor
Lower fibers at pectoralis major
Lower trapezius
Lower fibers of serratus anterior
Lower fibers of latissimus dorsi
Protractors of scapula (abduction)
Pectoralis minor
Pectoralis major
Serratus anterior
Rectractors of the scapula (adduction)
Rhom minor and major
Middle fibers of trapezius
Upper fibers of latissimus dorsi
Inferior rotators of the scapula
Levator scapulae
Rhomb major and minor
Pectoralis minor
Lower Pectoralis major
Superior rotators of the scapula
Trapezius, upper part
Trapezius, lower part
Serratus anterior
Shoulder joint
Also known as the glenohumeral joint
Bone ends - humerus
The single, large, long bone of the arm. The articular surface of the head forms 2/5ths of
a sphere and is covered with hyaline cartilage. It is considerably larger than the glenoid fossa with which it articulates - hence the great mobility of the shoulder joint. Note also the very short anatomical neck, which separates the head from the greater and lesser tubercles, which are in turn separated by the intertubercular groove (spanned by the transverse humeral ligament and holds the long head of biceps brachii). The surgical neck of the humerus is the upper end of the shaft of the bone, below the tubercles, and is a common site of fracture.
Bone ends - Scapula
The very shallow, pear shaped glenoid fossa of the scapula faces, in the anatomical
position, antero-laterally and is smaller in area than the articular surface of the head
of the humerus. It does not in any sense ‘hold’ the head of the humerus in position (cf
the acetabular fossa of the hip joint). The fibrocartilaginous glenoid labrum surrounds
the fossa but does little to improve stability of the joint.
Bursae
Minimise friction of tendons as they pass across bones or other tendons to their insertions
Rotator cuff muscles
Anterior
Subscapularis
Posterior
Supraspinatus
Infraspinatus
Teres minor
Subscapularis
Internally rotates arm
Supraspinatus
Abducts arm
Infraspinatus
Externally rotates arm
Teres minor
Externally rotates arm
Deltoid
Innervated by axillary nerve
Divided into three parts, anterior, posterior and middle fibres
Posterior fibres of deltoid
Extend shoulder
Externally rotates arm
Abduct / adducts arm with ant.fibres (depending on shoulder position)
Anterior fibres
Flex shoulder
Internally rotates arm
Abduct / adducts arm with post. fibres (depending on shoulder position)
Middle fibres
Multipennate
Abducts arm
Teres major
Internal rotation of arm
Adducts shoulder
Inserts on medial lip of intertubercular groove
Coracobrachialis
Adduction of shoulder
Inserts on medial side of humerus
Arm abductors
Supraspinatus
Deltoid, middle part
Arm adductors
Posterior
Latissimus Dorsi
Teres Major
Long head of triceps
Post deltoid
Anterior
Ant. deltoid
Pec. Major
Coracobrachialis
Arm flexors
Anterior deltoid
Clavicular head of pectoralis major
Coracobrachialis
Biceps brachii
Arm extensors
Posterior deltoid
Teres major
Latissimus dorsi
Long head of triceps
Sternocostal portion of pectoralis major
Internal rotators and External rotators
Internal
Pec. major
Ant. deltoid
Subscapularis
Latissimus dorsi
Teres Major
External
Post. deltoid
Infraspinatus
Teres minor
Organisation of arm
Anterior and posterior compartments are separated by medial and lateral muscular septa. Septa attach to medial and lateral supracondylar ridges of the humerus
Intermuscular septa are continuous with deep fascia
Anterior compartment
Coracobrachialis, biceps brachii and brachialis make up bulk
Posterior compartment
Triceps has three heads: long, lateral and medial.
The elbow
Three joints in one capsule
The humero-ulnar and humero-radial joints comprise a hinge joint with 135* of flexion/extension. The superior radio-ulnar joint provides for pronation and supination of the forearm.
Elbow ligaments
Triangular ulnar or medial collateral ligament. Ulnar nerve passes behind the medial epicondyle and lies on intermediate part of medial ligament
Radial or lateral collateral ligament extends from lateral epicondyle to the annular ligament
Annular ligament is attached to the edges of the radial notch of the ulna and surrounds the head of the radius. This allows the head of the ladius to spin during pronation and supination
Shunt muscles
Long head triceps
Deltoid
Short head biceps
Coracobrachialis
What do shunt muscles do?
Help prevent unwanted inferior movement of the humeral head at the shoulder joint during loading e.g carrying a heavy item
Biceps brachii
Supinator
Elbow flexor
Brachialis
Main elbow flexor
Coracobrachialis
Adduction of the shoulder
Triceps brachii
Elbow extensor
Carrying angle
Angle between radius and humerus
> 15* in males
< 15* in females
Functions of interosseous membrane
Hinge
Muscle attachment
Force transmission
Pronator/Supinator
Pronate/Supinate
Flexor/Extensor
Flexion/Extension
Abductor/Adductor
Abducts/Adducts
Palmaris
Palm
Carpi
Carpals of wrist
Digitorum
Digits or fingers
Pollicis
Thumb
Indicis
Index finger
Digiti minimi
Little finger
Radialis / Ulnaris
Radius / Ulnar
Superficialis / Profundus
Superficial / Deep
Teres
Round
Quadratus
Quadrangular (square)
Longus
Long
Brevis
Short
Anterior flexor compartment
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor digitorum superficialis
Flexor carpi ulnaris
Common origin from common flexor tendon of anterior aspect of medial epicondyle
Ulnar origin muscles (deep)
Flexor digitorum profundus and pronator quadratus
Flexor pollicis longus origin
Radius
Flexor carpi radialis insertion
base of 2nd metacarpal
Flexor carpi ulnaris insertion
Pisiform carpal bone
Muscles flexing the wrist
Flexor carpi radialis
Flexor carpi ulnaris
aided by palmaris longus
